Esserman, of course, maintains that he did not knowingly allow underage drinking - that he broke up the party when he discovered the booze.

But the law still raises an intriguing question: when parents purposely host these parties, are they encouraging reckless behavior or are they doing something more responsible - keeping an eye on teens who will drink anyway?

Before your humble blogger came to Rhode Island, I was a regular freelancer for the New York Times, covering suburbia. I wrote a piece in 2005 on the debate over this very question after two parents were arrested in the wake of a party in Greenburgh, New York. Here's an excerpt, with the first section focused more broadly on parental awareness around underage drinking and the second bit focused on social hosting in particular:

Another spotlight has recently been focused on under-age drinking by the Institute of Medicine and the National Research Council, which in September 2003 released a voluminous report on the topic. Written by substance-abuse and public-health experts, the tome warns that parents may be adding to the problem by tacitly supporting alcohol use or failing to get involved in their children's lives. And with research showing anti-alcohol messages have had little effect on young people, the report calls for a major advertising campaign directed instead at parents.

''It's clear that even though adults are aware of the issues of under-age drinking on a certain level, they are not aware of its magnitude and its seriousness,'' said Richard J. Bonnie, lead author of the report and director of the Institute of Law, Psychiatry and Public Policy at the University of Virginia. ''This is an endemic problem.''

Last year, almost 71 percent of high school seniors said they had consumed alcohol at some point in the last 12 months, down only slightly from 73 percent a decade earlier, according to the annual Monitoring the Future survey, sponsored by the National Institute on Drug Abuse and conducted by the University of Michigan.

The same survey found 94 percent of 12th graders describing alcohol as ''fairly easy'' or ''very easy'' to get. And the adult-sponsored party, it would appear, provides a prominent point of access.

Such parties are ''quite pervasive,'' said Kristie Long Foley, an assistant professor of public health sciences at Wake Forest University School of Medicine in Winston-Salem, N.C., and lead author of a recent study on the topic.

According to the report, which was published in the October edition of the Journal of Adolescent Health, 23 percent of teenagers say they have attended a party where a parent or a friend's parent has provided alcohol.

A handful of advocates say parents who have the parties are simply acknowledging the obvious: that many teenagers are going to drink no matter what they're told. ''You encourage them not to drink, you forbid them to drink, what if they drink anyway?'' said Marsha Rosenbaum, director of the liberal Drug Policy Alliance's Safety First Project. She added that some parents perceive having the parties as a ''fallback plan.''

But most experts say these parents, even the ones overtly looking out for teenagers' safety, are sending the wrong message. As Ms. Foley put it, ''They're condoning excessive alcohol use -- not intentionally -- but they are.''

Her study, based on interviews with 6,245 people ages 16 to 20, found that older teenagers who drank at adult-sponsored parties were twice as likely to have consumed alcohol in the last 30 days and twice as likely to have engaged in binge drinking in the last two weeks.

But somewhat paradoxically, while a party may encourage reckless behavior, the survey suggests that a glass of wine at a family dinner may actually teach responsible drinking. Teenagers who drank on such occasions with their parents were half as likely to have consumed alcohol in the past 30 days and one-third as likely to have engaged in binge drinking in the last two weeks.

''If you sit down and drink with your children,'' Ms. Foley said, ''it may protect them from excessive drinking behavior. It may very well be an acceptable thing to do.''